Pressure cookers, often referred to as steam digesters, are becoming increasingly popular as a result of increasing energy costs. A pressure cooker is a sealed vessel used in cooking, and does not permit air or liquids to escape below a preset pressure. As the boiling point of water goes up during the cooking, pressure builds up inside the cooker and the higher temperature attained shortens the cooking period. Literally, a pressure cooker is a modern day pot which our elders would seal properly with leaves after putting harder foods like beans and hard corn (ever hard of ‘Invungure’ or ‘Impengyeri’?) before cooking them. They would save a lot on firewood and time too. Invented by Denis Papin, a French Physicist in 1679, pressure cookers are mainly made from aluminium or stainless steel and vary in size and volume. While some are medium sized for use in an average household, there are huge ones that can be used in hotels and hospitals. Actually they are common in hospitals and are used to sterilise materials. Domestic pressure cookers are built and buffed up with three layers of heavy material that do not allow heat to escape and then are fitted with a copper clad bottom that conducts heat at a very fast rate. The lid is also fitted with a rubber ring which completely seals the main container, making it air tight. However, the lead is also fitted with a regulator which can be used when one is cooking high pressure foods like rice and beans. A safety valve on the regulator is pressed to allow extra pressure to escape. AdvantagesPressure cookers can be used to prepare a wide variety of recipes, covering most cooking styles and foods. The pressure cooker pan can be used as an ordinary saucepan for cooking larger quantities of food, reducing the number of utensils required. Pressure cookers are highly recommended for energy efficiency. They cut the amount of energy used and the monthly electricity bills. A modern pressure cooker can reach a maximum temperature of 125 °C (257 °F) in just four minutes. High temperatures cause the food to cook faster; normal cooking is reduced to up to 70 per cent. The high temperatures are a result of the high conductivity of heat, and the amount of steam trapped in an air tight container. Dry African beans take only 20 minutes to cook; fresh beans take approximately three minutes while most vegetables take a maximum of 2 minutes. Roast chicken is ready in 15 minutes while rice cooks for eight minutes instead of 45. Furthermore, the pressure cooker uses less water. Pressure cookers have a vital nutritional boost because the shorter cooking time and less water used mean that most nutrients and vitamins are maintained rather than being boiled away. The fact that no steam escapes, the natural flavour and minerals are all kept inside. Also the fact that food is cooked above the normal boiling point, all germs and viruses are killed including those that are thermal stable. Had a long and exhausting day of work, and don’t want to spend time preparing a meal? With all ingredients safely sealed in the container, you can put your feet up, take a shower or play with your kids until the food is ready. Ends
